1. Field of the Invention
The present invention relates to packaging of electronic components and more particularly concerns a three dimensional stack of electronic component layers having improved electrical current conduction between layers of the stack.
2. Description of the Related Art
High density packaging of electronic components and assemblies for various purposes is becoming more desired in many applications where space is limited. One method of efficiently packaging such assemblies is to provide individual planar printed circuit assemblies or individual planar multi-chip module assemblies, each on a separate layer or disc, and to stack a number of such layers or discs to provide a three dimensional electronic assembly. Such an arrangement is considerably more compact than the conventional single or double sided circuit board assembly where essentially all of the components lie in one or two planes.
Although the desirability of such three dimensional stacks of planar assemblies has been recognized, reliable arrangements for electrical interconnection of the individual layers of the stack have not been realized. Prior attempts to solve these problems have included solder, fixed interconnect wires, mating conventional electrical connections, metal on elastomer compressible contactors, button board contactors, and micro springs.
All of these methods have significant problems, particularly when applied to systems that may be expected to experience demanding environmental conditions, including high temperature, high acceleration and vibration. Among other disadvantages, many of the prior interconnecting devices and arrangements make the three dimensional assemblies difficult to assemble and disassemble for repair or replacement of parts. Reliable and separable connections between and among individual stacked planar packaging elements have not been heretofore available.
Accordingly, it is an object of the present invention to provide a compact, three dimensional electronic assembly that avoids or minimizes above mentioned problems.